Age is not the main factor, can it still do what it was designed to do, safely, is the question. I mow my grass with an 8-N Ford tractor (around 1949), nearly all small farms keep one around for odd jobs; not 80 years yet, but will still be running fine when it is. Ford didn't design them to last forever, but with modern oils they probably will.

OK Kool-Aide man. Nearly anywhere you dig anywhere, you hit limestone. where did it come from? How was it formed, how did it become a major component of the earths crust. Most any piece I pick up from my driveway shows where it came from, coal the same; oil, I have know idea where it came from ( I know you do, and how old it is, but can't prove it)
Anyhow, where did the co2 necessary to make the limestone come from, and what is the weight of co2 temporary sequestrated underground. It is coming back!

Who is acidifying the soil and why, or are you referring to rainwater which is slightly acidic. These underground rivers are not stagnant pools of water, the rivers flow to the sea, pump it out or not, the water is going away. I guess, one could pump to water out faster then it flows in, and cause a collapse, but it would have happened sooner or later anyway.

As long as NASA keeps safety first, nothing neat is ever going to happen there, astronauts will still die but by old age, boring. Nothing safer then sitting on the ground.
The current director tied to change the goal to "teaching the Arabs how important their culture was"; no matter how successful that was, it didn't make a rocket go up.

Hate to break environmental wackos ideas,but; some truth, sinkholes are common in nature without coal fires or mines. Florida, has more than most people can count and more every year, other States also. Underground rivers dissolve limestone, then collapse. Here is a link to wise up them that need to be learned.
http://www.dep.state.fl.us/geology/geologictopics/sinkhole/florida_sinkhole_poster.pdf
Also, old lava tubes/tunnels can collapse causing sinkholes.

"The increase is disturbing" Why? It's not real. Food is worse, maybe. When I was young we sifted flour to get the bugs out, more flour then bugs we used it, and yes the stuff coming out of the bugs, did not screen out. Moldy Ham, cut it off and it's good (I know ham is different now and it probably would kill you now). We used to, and I still do-very hard to find, drink raw cider-Apple juice. Nothing had expiration dates, if it smelled OK we ate it. Refrigerator didn't get near as cold as modern ones. Refrigerators used to kill a few people every-night, well it seemed like it, probably just a family or two every week.

Gold and silver coins are hard to counterfeit, hard to make fake gold, only takes about 20 Gold Eagles to buy a new car, not that much to lug around. Checks, credit cards and coins would work fine, plus no real inflation (Government theft).

Very well written argument and well reasoned, but, I was somewhat puffing up the typical yearly hype on what will kill us next, but you knew that. For the record: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0004522/ It will only kill 60+% of the people who get it, that's what it says, but we both know it won't, it's just puffed up Bull. All good vaccine makers have been driven out of business by ignorant lawsuits, all that's left are bureaucratic (Government) company's that can't get anything done. Don't you remember the vaccine that took years to develop a while back, then they made the wrong one; for some deadly Flu that never happened.
I'll also admit that if I drive 60 mi. at 60mph in an hour or so I'll be there.
The point about the Earth being the center of universe, was that it was settled, and of course it was logical. Galileo had to prove it was wrong. Technically, his proof was incorrect and he had to recant his finding and for other reasons. But he knew what he saw. Fighting the system can be dangerous, Louis Pasteur had the same problem since he wasn't a Doctor. Nothing about ulcers? For 20 Yr. the cause and cure was known, and in US Doctors were only allowed to treat symptoms; sad really for all the people that died of them.
The only thing not proved, and excepted on faith alone-GW. It is a Religion lead by Charlatans, but plenty of religions are. There are some who believe the Earth or life is only 6000 yr old, they can not be convinced otherwise, I no longer try.
You can not start new research on top of old if the old is wrong or just plain falsified.
Seriously, I do like you writing style, wish I could be that coherent with a thought.

I'm sure someone can help me on this; wasn't science settled on numerous things before? Like ulcers, smallpox, the earth was the center of Universe, D=RT (distance = rate times Time), Bird Flu will kill us all( new one every year). All these things were proved true and many more beliefs, and it was needed to be proven untrue- I know an oxymoron. Prove GW and quit with the name calling, to me, right now, it's just a religion.